In high-temperature metal pipe structure joining processes such as welding, brazing and soldering, flux is often applied to the intended contact surfaces of the pipe structures to prevent oxidation of the metal. Also, flux allows solder to flow easily on the pipe structure contact surfaces rather than forming beads as it would otherwise.
When joining other types of pipe structures, other agents may be applied to the pipes to facilitate the joining process. For example, when joining PVC pipe structures, a primer and PVC cement or adhesive may be applied to the intended pipe contact surfaces to join two pipe structures.
When applying agents such as flux, primer and adhesive to pipe structure surfaces, it is important that the correct amount of agent be applied, as well as applying the agent to a sufficient extent of the pipe structure surfaces.